is my hot water loop wrong?

bic2

hey all-



posted in the general forum about issues with the hot water loop coming off my steam system to heat the basement. got help and figured out that it might not be set up correctly. thought posting here might be more helpful in trying to sort it all out.



i'm a total newbie, so my question is very simple (or stupid?). how do i tell if it's set up correctly?



what i can tell you:

there is a heat exchanger, the water isn't coming straight out of the boiler.

it's a single loop with its own thermostat

there's a TACO 007-F5 pumping water from the boiler to the heat exchanger.

there's a TACO 007-F4-7 just upstream of the heat exchanger on the return side of the loop

when the thermostat calls for heat, the pump and the boiler kick on

the loop gets hot and the basement warms up

the radiators upstairs start to get hot

bic2

hello all -- want to ping back on this post from last winter. still trying to sort out the hot water loop off of my steam boiler. Any input is MUCH appreciated!

Rich_49

Pictures please

DanHolohan

Is the upstairs thermost calling for heat while the downstairs zone is running?

bic2

here is a pic that hopefully shows a little. i can send more if it helps.

the loop will cause the boiler to fire and make steam regardless of whether the upstairs thermostat calls for heat or not.

Zman

How long has the problem existed?
I think you have controls issue. Normally a call for heat from the steam system upstairs will trigger the boiler to boil and produce steam until it reaches the set pressure.
During a call for heat downstairs the boiler should not boil and produce steam it should only come up to a setpoint temp below boiling.
Unless you are fairly handy with voltage meter, you may need some help with this one.

Carl

bic2

I've only been in the house for 1 winter and I had the problem then.

I think there are definitely control issues (i.e. a broken aquastat) but I guess I'm wondering whether there are ALSO issues with the system layout and design itself. Hoping someone might be able to look at the pic and tell me. A control problem I could imagine fixing -- anything else and I'll probably just forget about it.

Zman

If you follow the wire from your aquastat labeled on your pictured back to the controller on the boiler that may help.
A picture and model.

Charlie from wmass

A. Siezed circulator on the boiler side of the heat exchanger or air on the baseboard side of the loop.

icesailor

You need to hire a heating Professional that knows what they are looking at.

Don't just "Forget About It". Its not a serious problem. Make it right.

Ironman

Another issue that you may have: the steam piping off the boiler doesn't look correct. It's hard to tell from your pics, but any modern steam boiler should have a header. You cannot pipe it like an older one that had a large steam chest.

Do you get any hammering in the pipes when it's making steam?

Zman

@Charlie from wmass.
His baseboard heat loop works fine.
The boiler is making steam when it should not.
A control issue

bic2

hi all-

sorry i didn't reply to all your helpful posts -- i don't see where i can get email notifications of new posts on the thread. Anybody know how to do that?

In any case, I do think it's a control issue because the baseboard does get hot when the system is calling for heat. The problem is that the boiler never turns off, so eventually the water in the baseboard get really hot and I get steam upstairs. I was hoping to be able to diagnose what the control problem is, but I have no experience with that. Any advice how to:

1) Check whether the aquastat and pumps are working as they should.
2) Check whether the wiring is set up correctly.
3) Check whether there is enough water in the baseboard loop.

As for the near boiler piping, I know it's wrong. It was wrong when I bought the house, but it's not really practical to fix it.

DanHolohan

To get email notifications, click the star at the top of the thread. When it turns yellow, you're all set.

bic2

a-ha! thanks!

(if only fixing my heat was that easy!)

bic2

Just to follow up on this, can someone explain to me how a system like this is supposed to be set-up and controlled? All I know at this point is that when the loop calls for heat, it pulls hot water from the boiler into the heat exchanger, which is then used to heat a second loop that actually runs through the baseboards.

bic2

or recommend a book or point me to a thread?

Zman

Your upstairs heat is working correctly.
Your downstairs heats perfectly except it causes the upstairs to heat at the same time.
The boiler is making steam when it should not.
This is a boiler control issue.
If you post a picture and a model of the boiler controller, this can be resolved. The aquastat on the heat exchanger is not the boiler controller, it is however connected to it.

bic2

thanks -- you are right that it is a controller issue, i'm just not sure what the specific issue is, or how to fix it. i will post some pics when i get home tonight and hopefully I can sort it out with some help.

RobG

Basically. on a call for heat from the baseboard loop, the boiler should fire and heat the water to say 180 deg, not enough to make steam but hot enough to heat the basement. When the steam heat calls, it overrides the baseboard aquastat and makes steam, but for some reason you are making steam as well as hot water on a call for just the hot water loop. Does that make sense?

Rob

bic2

yeah -- that makes perfect sense. my question is HOW should be pumps/aquastat/boiler be set up so that happens correctly?

hoping that if i know the right way, i can figure out what's wrong...

my guess (based on common sense alone and no actual knowledge) is that the thermostat turns on everything (boiler, pump from boiler to exchanger and baseboard pump), and then when the aquastat sees that the temp in the heat exchanger is too high it kills the boiler. Presumably at that point the pump in the baseboard loop stays on to keep circulating that hot water. Not sure if they pump from the boiler to the exchanger should stay on or not.

Harvey Ramer

I don't know how your control is setup and I have never actually seen this application in the field, but...

If I was tasked with setting this up, this is how I would do it.

Materials:
(1) single zone pump relays
(1) thermostat
(1) triple aquastat relay
wire
pumps already there

Thermostat goes to the SZPR and energizes the boiler pump, sends power to the TAR (location of current aqua stat). The TT terminals on the TAR are jumpered. The TAR will control the basement circulator and control high and low limit on the boiler while providing protection against cold water return. The power going from the TAR to the burner would be wired in parallel with existing burner control. ALL POWER FOR THE BOILER AND CONTROLS MUST COME FROM 1 DISCONNECT SWITCH 120VOLT.

I'm sure that's not the only way to do it but it might give you the concept to troubleshoot what you have.

Harvey

Zman

You have to post what you have. Otherwise it is just guessing.
You plan would work if the aquastat has a cutout feature.

JStar

That's the wrong circulator choice for the boiler-side of the Heat Exchanger. It should be a 3-piece bronze circulator. Any wet-rotor pump uses water to cool its motor which, with steam, will destroy the pump.

This setup can be made much simpler by removing the HX and staying with one correct circulator, or by keeping what's there and installing one switching relay and a properly placed aquastat.

bic2

Hey-

Thanks for all the help. Here are some pics that will hopefully help.

The brown wire all the way at the left in the controller is the one from the aquastat.

HELP!

Zman

Ok,
Where do the wires on A and R on the Argo controller go?
Which terminals are the wires attached to on the aqua-stat?

bic2

thanks zman -- i'm not at home right now, but i'll check once i am.

sorry, but i'm a total newbie at controllers and stuff. Which are the A and R wires?

Zman

There are couple terminals on the bottom that are likely labeled

bic2

ok. i checked out the wiring and to my ignorant eye it looks a little weird. I was trying to explain it but then realized it would probably be simpler just to draw a picture.

can you let me know if this is correct?
thanks

Zman

Are you wired to R&B on the aquastat or R&W?

bic2

The aquastat is wired with red and white as its shown in the pic to the top two terminals.

Zman

The actual terminal on that should be labeled R W B.
The way you are set up you should be wired to R and B.
Can you read the terminals?
How are you with a multimeter?
The manual shows those as top and bottom.
You won't hurt any thing if you try the white wire on the bottom and set the aquastat to 180

bic2

sorry, can you explain that a little more?

you're saying that I should move the white wire from the middle terminal of the aquastat to the bottom? Can you explain why?

I actually just got a multimeter today figuring i might need it, but have no experience with it.

Zman

The way you are wired may be correct and you just have a bad aquastat. I am just trying to verify the present wiring.
The way the installer intended for this to work is for the aquastat to interrupt the zone controllers call for heat to the boiler anytime the temp at the aquastat goes above the setpoint temp on the dial.This would leave the circs running but turn the boiler off before it generates steam.
If you take disconnect the wires and use an multimeter in OHM mode, you can verify the function of the aquastat.

bic2

that setup makes sense, so if that's how it's wired then something else must be wrong since that's not how it actually behaves.

how do i do the test with the multimeter? What am i looking for?

sorry to ask so many questions, i'm completely ignorant about this stuff. i really appreciate the help.

Zman

The aquastat is what's called a SPDT (single pole double throw) switch. If you wire it one way it will close the circuit when the temp reaches the setpoint on the dial.If you wire it the other way it will open the circuit when the temp reaches the setpoint on the dial.
They do go bad from time to time.

Zman

I was just looking over your wiring drawing. There is a problem with the connections in the controller.
The brown wire going from A&R to the boiler is always telling the boiler to fire as it is bipassing the switch to your aquastat.

For trouble shooting, disconnect the brown wire. You are going to eventually going to pull the upstairs t stat wires off the T1 terminals and connect them to the brown wire with wire nuts.

bic2

hey all-

with massive help from Zman I think I have this sorted out. Here's my debrief:
After looking at my wiring diagram (posted earlier in this thread) Zman noticed that the brown wire running from the controller to the boiler was actually short circuiting the loop from the aquastat to the boiler. Not sure why it had been wired this way, but eliminating that wire altogether made things work for the heat loop. That connection was needed to get the upstairs thermostat to kick the boiler on, though. I first wired it directly to the priority terminals on the controller but then, to simplify things and eliminate possible weirdness, just connected that brown wire directly to the thermostat wire coming down from upstairs.

updated schematic posted here of the current wiring setup.

i'll have to wait until it gets a bit colder outside to really see if it's robustly working, but everything seems correct at this point

Thanks, all, for the massive help.